Coal cleaning apparatus



5 Sheets-Sheet l M INVENTOR A; MAZ/gm M. E. HAWORTH GOAL CLEANING APPARATUS Filed April 9, 1951 Jan. 28, 1936.

Jan. 2 8, 1936. M. E. HAwoR'rH COAL CLEANING APPARATUS Filed April 9, 1931 5 Sheets-Sheet 2 INV NTOR T TT T T TTTTTTTTTTTTT T RS 121.15

T TTTTT T TT /f//ff//f M. E. HAWORTH COAL CLEANING APPARATUS Filed Apr-11 9, 19:51

Jan. 2s, ,1936.

`Ian. 28, 1936.

MMMWW TNTTT M. E. HAWORTH coALcLEANING APPARATUS Filed April 9, 1931 5 Sheets-Sheet 4 Jan. 28, 1936. M. E. HAwoRTl-l coAL CLEANING APPARATUS Filed April 9, 1931 5 Sheets-Sheet 5 @MA/72cm ML@ www@ Patented Jan. 2s, 1936 UNITED STATES PATENT OFFICE COAL CLEANING APPARATUS of Ohio Applicatitn April 9, 1931, serial No. 528,725

17 Claims.

This invention relates to coal cleaning apparatus and particularly to an apparatus of the dry or pneumatic type which is provided with new and improved means for controlling the refuse.

While there are many known constructions for carrying out the dry or pneumatic separation of a solid mixture of constituents of varying specic gravities, there has been no particularly eicient arrangement available heretofore for controlling the refuse or other constituents of the dry mixture which are the impurities or adulterating ingredients which are to be separated from the fraction of the material to be recovered.

r One of the objects of my invention is to provide an apparatus for cleaning coal, for example, whereby the remaining constituents, other than the coal and hereinafter designated as refuse, are efciently and rapidly separated from the coal so as to obtain a clean coal concentrate.

-A further object is to provide a coal cleaning apparatus which has in predetermined positions with respect thereto a plurality of refuse ejectors for positively removing the refuse at a predeterminable rate.

A further object is to provide such refuse ejectors with means for varying their eiective rate of discharge and this may be done either by varying the capacity of the individual ejectors and/or by increasing the speed Vof operation of said ejecktors separately or together.

A further object is to provide means for guiding such refuse to said'refuse ejectors and to make such means adjustable so as to'predeterminev the amount and rate at which said refuse is fed to said ejectors, which latter may theny be so adjusted as to remove the refuse at a rate of speed substantially the same as that at, which it is fed thereto. Other and further objects and advantages will 40 either be understood from the following disclosure or will be appreciated by those skilled in this particular art.

In the accompanying drawings: Figure 1 is a plan view of a coal cleaning ap.-

parat-us embodying the present invention with Fig. 5 is a View similar to the lower portion of Fig. 4 on an enlarged scale but through a different portion of the apparatus.

Fig. 6 is a general perspective view ofthe apparatus of Fig. 1 with cooperating superstructural 5 parts taken substantially along line VI-VI thereof; and

Figs. '1, 8, and 9 represent diagrammatically times of settling under various conditions.

Similar numerals refer to similar parts l0 throughout the several views.

One of the important features of the coal cleaning apparatus of my present invention is the deck member on which the action takes place. This deck is composed primarily of a so-called upper 1I section I0 and an inclined section Il, preferably angularly disposed with relation to each other as indicated in Fig. 1. Each said deck portion is perforated as at I2 in the manner known in the industry. An eccentric drive means indicated as I a whole by I3 is conventionally provided for the usual purposes of imparting a desired movement or stroke to the deck. The general arrangement is further clearly shown in Fig. 6 which further indicates that the eccentric drive operates direct- I ly on deck supporting frames I4 to which the deck is suitably secured. These deck supporting frames are connected by cantilever springs I5 as clearly indicated in Fig. 6. Below the eccentric drive there is a hinge I6 for changing the l. longitudinal slope of the deck supporting frames and hence of the deck. The adjustment of the slope may be secured by means of the screw jack arrangement I'I which is provided at the opposite ends of the frames. This adjustment takes] place 35 relatively to the top of the oor surface indicated by I8. The lateral slope of the deck may also be varied and for this purpose there are provided the hinges I 9 between the deck supporting frames in such a manner as to permit of the desired ad- 40 justment, which may be effected by screw Jack means I9.

Enclosing the surface of the deck are the side boards 20, the configuration of which is clearly apparent from Figs. 1 and 6. 'I'hese side boards, 45 as indicated, extend above the top oi.' the deck sections and to such a height as will be above the bed of coal or other material formed thereon. The only portion where the "side boards are omitted is at the lower end of the inclined secl. tion `designated as the clean coal discharge (chute) and identified by the numeral 2|.

Extending substantiallyv from Athe point' 22 where the side boards meet atan acute angle between the upper and inclined deck sections to neotion with refuse ejectors 126, there i vseal M spring hinged3at li. I Each of the pockets above referred to is variable -surface of both deck sections as indicated in Fig.

1. The baiiie 24 permits the lightest material in the upper strata ofthe bed of coal to flow from the upper section to the inclined section at the point nearest the intersection ci the baiile with the side boards. At points successively nearer the opposite end of the deck section, successive intermediate strata of the bed which has stratifled on the deck, in the usual manner, are permitted to iiow ento the inclined deck section :and these materials are of heavier gravity than the coal which, as is known, constitutes the lightest fraction of the mixture.

The end of the upper deck section near the y eccentric drive is known as the feed end. Disposed along the end of the upper deck section opposite to said feed end and also along the ad.- jacentside ofthe inclined deck section are the refuse ejectors 26. These consist generally of a rotatable member having pockets for the reception of refuse which is discharged when the particularv pocket has made a revolution oi approximately 180 and a chute member 2l of suitable construction. These ejectors may be driven by shafts-28 there being bevei gears 29 interposed when necessary; for example, when the shaft takes a turn or has an angie in it as shown in Fig. l. This common shaft is. provided with a suitable pulley which is belt connected at 3i to a suitable pulley 32 connected to a. variable speed drive arrangement indicated in general by 33. This variable speed drive is disposed upon a suitable hinged support 36 having hinge and adjusting screw jack means 36 as shown in Fig. 2 so that the drive may be suitably inclined and its laterai slope varied according to the inclination of the deck fsb as to maintain the eiciency and effectiveness of the drive. In cons an air in its capacity by means of a suitable adjustable membrane or partition, or the like 3l, see Figs. 4

and 5, so las to cause a predeterminable amount of refuse to be taken up thereby. .This is desirable especially because itis not desired to dep'iete the depth of the bed at thev point the eject-ors are operating as this would cause an undesirable mingling of the various'strata of. the bed. Thus the bed is allowed to assume its proper depth after an interval and then the capacity of the ejectors is so adjusted that the refuse will thereafter be removed at substantially the same rate at which it is received at the points where the ejectors are operating. In orderv to increase the efficiency of the ejectors and the effectiveness ci the cleaning operation as a whole, deectors 33 are provided, which constitute a means for guiding refuse to the ejectors. These defiectors 38 are generally triangular shaped plates as seen in Fig. 4, for example, and they are so arranged with respect to the .deck as to be adjustable in position. The arrangement is clearly shown in 1. Due to the arrangement hereinbefore'described the ejectors progressively discharge refuse of a. decreasing specificgravity as considered with respect to a direction suitabiyf` from the variable speed drive to the clean coal discharge (chute 2l). `Any eoal which is discharged by any of the refuse ejectors may be easily recovered by recirculating the refuse containing the same and this is merely done by feeding such material back onto the deck at the feed end thereof, where it undergoes again a, stratification due to the stroke imparted to the deck and the air'or fluid stream-passing up through the perforations in the deck, said stream being generated by suitable blast means as will be hereinafter understood more fully.

Above the deck are arranged the hoods 39 all connected by suitablenecks 40 to a common main 4l in which suction is created so that the dust and other :tine particles rising from the bed may be recovered if desired and at the same time be prevented from becoming a nuisance or a source of danger. The coal, in the form of coal dust, which is in said material may be also suitably recovered therefrom, and I may for that purpose, put it through a similar process to the present adjusted for taking care of 1ines.

In connection with said suction hoods 39, adjustable louvers t2 are, however, provided therein and adjustable louvers 43 are additionally provided below the deck sections. These matters will be understandable from my hereinafter specified copending applications.

Farther details as to the suction arrangement and as to the air blast below the deck form no part of the present invention but are described and claimed in my copending applications Serial Numbers 448,493, filed April 30, 1930, and 554,254 filed July 31, 1931.

'I'he above is intended for` illustrative purposes and the operation thereof yWill be understood therefrom. The coal mixture is, however, fed onto the upper deck section at the leftv or feed end of the same. This deck section may be horizontal both longitudinally and transversely; or horizontal transversely and inclined upward or downward iongitudinally; or inclined upward or downward transversely and horizontal or in,- clined upward or downward longitudinally. The rifiies of this deck section may be parallel with the long side thereof or inclined laterally thereto..

.They may as high as an inch or more.

The inclined deck section has riilies parallel with the clean coal discharge edge or disposed laterally with respect thereto. This section extends generally laterally toward` the feed end of the upper deck section and may ne horizontalV or inclined laterally or longitudinalis7 as explained above regarding said upper deck section.

, .The movable deiiectors 38 are set so that light gravity materials, whichh comprise the coal and which are forced to a position on top of the refuse, flow away from the ejectors to be discharged iinally with the clean coal at the lower end of the inclined de'ck section.

The speed and capacity ef the ejectors are regulated toremove refuse only so fast as it' is received in the ejector pockets. By so regulating the capacity of the pockets, the 'material in time will be largely refuse-or heavy gravity material. The pockets comprising the ejectors being limited in their capacity are always full and the refuse having a considerable depth of bed tends to over ll the pockets causing the material to take its natural plane of repose. Any lighter gravity .materials that might accidentally be on the top or material in the pocketl will drop off as the material takes its repose.

The space between the movable deectors,

aoaaooa therefore, is maintained full of refuse as the speed of operation of the ejectors is so regulated as to remove the refuse only so fast as it is deposited in the space or pockets between the deflectors.

Materials in the upper deck section are regulated to maintain a constant depth of bed from the feed end to the beginning of the tapered baille. The material in the section of the deck from the beginning of the tapered baille to the ejectors may vary somewhat in depth. 'Ihe material on the inclined section of the deck may vary in depth from the maximum depth at the top of the inclined section to the minimum depth at the bottom of the inclined section. 'Ihis is the natural consequence, inasmuch as the discharge from the upper deck section to the inclined deck section is at the same rate as the feed to the table. The speed of travel of the material cn the inclined deck section may be regulated to exceed the speed of travel in the upper deck section. As some of the material is ejected as refuse, less material is discharged as clean coal and, therefore, the depth of bed somewhat less at the lower end of the inclined section than in the upper deck section. These depths of bed, however, and speeds of travel may be regulated as desired if lit is found convenient to maintain a uniform depth of bed throughout the upper and inclined sections of the deck.

As the material passes from the feed end of the deck toward the ejeotors, stratification takes place, the heavier gravity particles depositing themselves in the lower strata of the bed and the lighter gravity particles rising to the upper strata of the bed. 'Ihe heavier gravity particles in the lower strata, being confined between the riilies, are conveyed longitudinally and laterally along the surface of the deck by means of the motion applied to the table through mechanical means and deposited between the movable dellectors, this heavier gravity material piles up in these pockets and forces any lighter gravity materials that may be mixed with same to the lupper strata of the bed. The deectors are so inclined as to permit the lighter gravity material, under the action of air, to ow back toward the feed end of the table and join the other lighter gravity materials which are finally discharged as clean coal.

It should be understood that when the pervious deck is oscillat-ed the materials advance forwardly along the main section I toward the front board 20 which acts as a banking wall for the uppermost strata which will then move laterally toward the inclined and rearwardly branching section I I. On account of the downward gradient of the upper surface of the layer of materials on the section I0 and on account of the depth of such material, that portion moving along the baille plate 2li will move over the top of the same onto the inclined section II. The tapering form of the baille plate 24 delays this movement onto the section II until it is near the forward end of the baille plate 24. Some of the material which nds its way over the upper edge of the baille plate 24 tends to move transversely of the riffles on the section II. The front board 20 on the section I I is relied on to form a banking wall so that the uppermost strata tends to move rearwardly toward the rear wall of the section I I. Consequently, on account of the rearward branching of the section II the oscillation of the ydeck will stratify the materials more elliciently to secure movement of the lowermost stratum toward the ejectors -distributed along the/front wall of the section I I.` Furthermore, the banking action of the uppermost strata and the movement thereof toward the discharge opening 2I makes it desirable to have the deilector plates downwardly inclined along their upper edges as shown in Fig. 5. It will also be seen that after any ejector in the series has removed material from thelowermost stratum the remaining materials constitute a different mixture. classifying progressively the materials removed according to their specific gravities so that the material which moves rearwardly and downwardly along the section I I to the discharge opening 2I will be clean coal.

As the materials travel down the inclined deck section further stratification takes place and any materials heavier in gravity than the clean coal and referred to herein as refuse that has not been removed by previous ejectors is conveyed to succeeding ejectors. Finally all heavier gravity materials are removed with only clean coal remaining in the bed at the lower end of the inclined section. If at this point, it becomes necessary to remove a small amount of clean coal with the refuse in the last ejector, the material discharged by this ejector can be recirculated to the feed end of the table in order that a clean cut separation of coal from its refuse and impurities may be made.

I have found from experimentation and from practice that in order to produce free settling action in the coal bed which permits the heavier gravity materials to settle into the lower strata of the bed that certain effective buoyancies are required. The value of the buoyancies required are determined by the density of the materials being separated and the volumes of air required are determined by the density of the fluid stream. For example, where it is desired to suspend materials having a specific gravity of 1.40 or lighter in the upper strata of the bed and materials of gravity heavier than 1.40 in the lower strata, the buoyancy of the fluid stream is regulated so as to hold materials of 1.40 gravity and lighter, in suspension, while at the same time being insuilicient to hold the heavier gravity materials in full suspension permitting them tordescend into the lower strata. In this case, the heaviest gravity materials or materials of 1.75 and greater, for example, will be completely out of the suspension and in the lower strata of the bed. Materials between 1.40 and 1.70 gravity may be partially in suspension and between the uppermost and lowermost strata of the bed. Under the same conditions of buoyancy, these materials will eventually settle, but the time of settling will be greater than the time required for materials of 1.75 gravity and heavier, as per illustration shown on the drawings. Several methods may be employed for producing the desired settling action as illustrated on the drawings.

More eifective stratication and separation of lighter gravity materials may be effected after the heavier gravity materials or material of 1.75 gravity and heavier are removed, by reducing the buoyancy of the fluid stream to a value that will permit free settling, holding the materials of 1.40 gravity and lighter in suspension and at the same time permitting materials heavier than 1.40 gravity to settle to the lower strata.

Assuming a constant depth of bed, and materials of 1.75 gravity and greater. the buoyancy .s adjusted to permit materials of 1.75 gravity Therefore the ejectors are a means of -also that depending upon and greater to settle to the lowermost stratum. After having removed materials of this gravity, the fluid stream may be altered so as to reduce the buoyancy to an extent where materials of 1.60 gravity, for example, are permitted to settle. Other sections of the deck are arranged progressively and the uid stream adjusted so as to permit materials of 1.50 gravity, 1.45 gravity, etc. to settle successively to the lower strata on different sections of the deck. The result is that the ejectors nearest the feed end of the table discharge heavier gravity refuse, Whereas the ejectors near the discharge end of the tabledischarge mostly lighter gravity refuse. The gravity of the refuse between these ejectors ranges from heavier to lighter.

One inherentcharacteristic of any type of blower is that asthe resistance to the flow of air increases, the volume produced by a fan at a constant speed varies inversely with the resistance to the flow.

The buoyancy produced by an air flow is proportional to the volume and density of air and inversely to the resistance against which it flows.

I have by means of experimental work determined the volumes of air required to flow through beds of different materials in order to produce the buoyancy required for free settling at certain specific gravities. Furthermore, the ow of air required can be regulated by applying perforated plates or sub-decks containing certain definite percentages of open area under the separating deck and at sufficient distance below the separating deck to permit the airto be distributed evenly through the separating deck. Knowing the volumes required for buoyancy at any condition of air density, the resistances of various materials to the flow of air, and the resistances perforated plates and other pervious materials develop against the ow of air, I have been able to predeterm-ine the volumes of air required (for any value of air density) to produce buoyancies ofcertain definite values required for free settling stratification. .f

I have `by means fof 'experimental work also determined the vol es of air required to produce the buoyancieszf'dr mixtures containing diierent ranges of sizes of constituent particles as well as fordiierent percentages of various sizes in the mixtitirajv Depending upon the character of the impurities iifa mixture; the relative sizes and specific gravities of the respective particles comprising the impurities; and the relationship of the particles of impurities to the particles comprising the whole mixture of coal and impurities as to number, size and shape; I have found from experience that with certain mixtures air streams may be adjusted to produce and maintain buoyancies that permit the removal of certain sizes and shapes of particles of impurities of one specic gravity together with certain sizes and shapes of particles of impurities of other specific gravities. In other words, for example, refuse containing larger sized particles of 1.50 to 1.60 gravity materials may be settled under the influence of certain buoyancies the same ejectors and at the same time that smaller sized particles of 1.75 gravity or heavier are settled and removed. l

Therefore, the invention hereindescribed further comprises the regulation of air streams and the maintenance of buoyancies of certain xed and denite values, the settling and removal of impurities of certain specic gravities implying the mixtures underand removed by means of going the separating process a selection as to speciic gravity also implies a selection as to size of particles removed as impurities.

I have found, for example, in separating minus one-half inch by zero mixtures that impurities of boney structure fairly large in size and approaching the clean coal concentrate in specic gravity, can be removed by means of the same ejectors and at the same time as impurities more dense in structure, very small in size and heavy in specific gravity, thus permitting the removal of the impurities of all sizes and specific gravities from a mixture; the impurities of certain sizes and specic gravities being removed by means of the same ejectors together with the impurities of other sizes and specicgravities; whereas, with certain other mixtures of different sizes and containing different ranges of sizes in the mixture the impurities contained in certain successive ejectors conform more closely to the progressive specic gravities mentioned.

From ai consideration of the foregoing it will be understood that Fig. 7 illustrates the difference in time of settling required for material of different specic gravities in a bed of materials under the influence of air streams having a certain definite value of buoyancy throughout the deck area; that Fig. 8 illustrates a method for accelerating settling of heavy gravity materials by regulating the air streams, hence buoyancies and bed resistances, by means of a subdeck and louvers which develop resistances to air flow, thereby reducing the volumes through various sections of the bed and deck and reducing buoyancies, allowing dierent gravity material to settle freely in different sections of deck; and that Fig. 9 illustrates a/methodcfor producing free settling of various gravity materials by regulating the depth of bed and hence the air volumes to develop the buoyancies required for free setference in pressure between areas A and D has a that between -B and D a diierent C and D a still diierent certain value; value; and that between value. l

As shown diagrammatically in Figs. 8 and 9, the space below the sub-deck is divided into separate rectangular sections each bounded by four vertical walls with an adjustable louver located in each section. Between the sub-deck and the upper deck rectangular or box-shaped spaces are also partitioned off. Such box-like chambers below the sub-deck communicate through the perforations in the sub-deck with the box-like chambers immediately above the same and such box-like chambers are distributed over the entire spaces below the main section I0 and the rearwardly branching and downwardly inclined section Il. In this manner the adjustable louvers in the lower box-like chambers may be relied on to regulate the fluid-pressure in accordance with the materials on the impervious deck sections as explained above. For instance, after the rst ejector has removed the heaviest parejector, and ejectors.

What I claim as new and desire to secure by Letters Patent is:

1 In a device of the character described, an upper deck section and an inclined deck section, a. sideboard along the same rising above the deck surface suicient height to prevent material flowing thereover, riliies on said sections of appreciably less height than said sideboard, and a baille between said sections, extending from said sideboard toward the opposite portion of the deck and tapering from a height equal to the sideboard at the sideboard to a height vequal to the height of the riilies at the end of the baiiie.

2. A coal cleaning apparatus comprising a main perforated deck, a supplemental perforated so on along the whole series of deck branching laterally and rearwardly from one side of the forward end portion of said main deck, a plurality of spaced guiding devices on the main'v deck, a plurality of spaced riiiles on the supplemental deck, means for stratifying the materials on said decks according to the specific gravities ofthe constituents thereof, means for progressively removing the lowermost strata from the forward edges of said decks and discharging the lightest material from that end of said supplemental deck remote from said main deck.

3. A coal cleaning apparatus comprising a deck, guiding means extending along said deck, means for stratifying materials on said deck according to the specic gravities ofthe constituents thereof, means for collecting the lightest gravity constituent, means comprising a plurality" of ejectors .for positively removing the remainder of said constituents in fractions of progressively decreasing specific gravities at a rate of speed substantially equal to the delivery thereof to said removing means, mechanism for positively driving said ejectors, and a plurality of deflectors one for each of said ejectors and each having an upper edge inclined downwardly toward said deck for guiding the remainder of said constituents to said ejectors while directing toward said collecting means the lightest gravity constituent.

4. A coal cleaning apparatus comprising a main pervious deck, a supplemental pervious deck branching rearwardly from the forward end portion of said main-deck and inclined downwardly, riiiles on both of said decks, means for stratifying materials on said decks. according to the specific gravities of the constituents thereofy and for causing said materials to advance therealong, means affording collection/f clean coal from the end of said supplemental deck, and mechanism affording collection of the'other constituents at the front end of said main deck and at the front side of said supplemental deck.

5. A coal cleaning apparatus comprising a main deck, a supplemental deck branching rearwardly from the forward end portion of said main deck, guiding means on both decks, means for stratifyingmaterials on said decks according to the specic gravities of the constituents thereof and for causing said materials to advance therealong, means affording collection of the lightest gravity material from the lateral end of said supplemental deck, and means aiording discharge at intervals along the front sides of said main and supplemental decks of the other constituents o1' said materialsv according to `progressively decreasing speciagravities.

6. A coal cleaning apparatus comprising a main pervious deck, a supplemental pervious deck branching rearwardly from one side of the forward end portion of said main deck and inclined downwardly, means for stratifying materials on said decks according to the specific gravities of the constituents thereof and for causing said materials to advance therealong, means affording collection of the lightest gravity material" from the lower end of said supplemental deck, and means affording discharge at intervals along the front sides of said main and supplemental decks of the other constituents of said materials according to progressively decreasing specific gravities.

7. A coal cleaning apparatus embodying a main pervious deck, a supplemental pervious deck branching rearwardly from the forward end portion of said main deck, riiiles on both decks, means for stratifying said decks according to the specific gravities of the constituents thereof and for causing said materials to advance therealong, means affording recovery of clean coal from the lateral end of said supplemental deck, and means affording reccvery of the remainder of said constituents at the front sides of said main and supplemental decks, said last-named means comprising a plurality of spaced-apart ejectors distributed along said front sides.

8. A coal cleaning apparatus comprising a main pervious deck, a supplemental pervious deck branching rearwardly from the front end portion of said main deck, spaced riliies on both decks, means for stratifying materials on said desks according to the specific gravities of the constituents thereof and causing said materials to advance therealong, means alfording recovery of the clean coal from the lateral end of saidsupplemental deck, upright banking walls at the' front ends of said decks, a plurality of ejectors spaced apart and distributed along the front ends of said decks at the bases of said walls, and means for operating said ejectors to discharge the other constituents according to progressively decreas-' ing specific gravities.

9. A coal cleaning apparatus comprising a main pervious deck, a supplemental pervious deck branching laterally and rearwardly from one side of the forward end portion of said lmain deck, a continuous upright wall extending transversely of the forward end of said main deck and the front side of said supplemental deck, a plurality of positively voperated ejectors distributed along said wall, means for stratifying materials on said decks according to the specific gravities of the constituents thereof and for causing the lowermost strata to advance toward said wall and for causing the lightest gravity material to flow along said decks including the rear side portionv of said supplemental deck to a discharge opening at the lateral-end offsaid supplemental deck, a plurality of ejectors distributed along said wall, and guiding means on said decks for directing the lowermost strata to said ejectors.

10. A coal cleaning apparatus comprising an elongated pervious deck, side walls at the lateral edges of said deck, a transverse wall at the forward end of said deck, a supplemental deck branching rearwardly from an opening in the front end of one of saidside walls, front and rear walls connected respectively to said transverse wall and to the adjacent side wall of said main deck, ejectors distributed along said front materials on' vet walls, riles on said decks leading to said ejectors, means for stratifying materials on said decks according to the specific gravities of` the coistituents thereof and to cause the lowermost Yrstrata move along said riiiles to said ejectors and to cause the 'lightest gravity material to movie to a discharge opening at the end of said branching deck, and means for positively pperating said ejectors. v il; Y

11. A coal cleaning apparatus; comprising a deck having an elongated section and a rearwardly branching section downwardly inclined, an upright banking wallrron the forward end of said deck, a plurality of electors distributed along the forward end Vof said deck at the base of said wall, adjustable upright deflector plates one associated with each of saidejectors, spaced riiiles on said deck and leading toward said banking wall, means for s'tratifyingv the materials on said deck according to the specific gravities of the constituents thereof, and means for operatingY said ejectors to recover the lowermost strata acy cording to progressively decreasing specific grav-Q the lightest gravity constituent is beed from the Yend of Ysaid branchingL77 section. i n i Q 12. In dry cleaning apparatus the ccmbina-fV tion with a deck having a main section and a .rearwardly branching downwardly inclined suplplemental section, a'sideboard extending along that side of the main section adjacentlto said Supplemental section and rising above the surace of the deck of the main section suflcient to nconfine materialjto said deck, riiriles on said sections of'less height than said sideboard, and a baille extendinglfrom the forward end of said* sideboard with its upper edgeftapering downwardly from approximately the height thereof to the space where said defek sections communicate.V 13. In coal cleaning apparatus, the combination with a main deckg of a supplemental deck branching rearwardlyfrgorn the forward end portion of said main deckgan upright banking wallY at the front side of said supplemental deck, means for stratifyingmateriais on said decks in accordance withthe specific gravities thereof, an upright sideboard for that side of the main deck Y adjacent to said supplemental deck, a baille connectecgto the forward end of said sideboard and 50 tapering downwardly toward said banking wall, Y. and means distributedalong the front edge of said supplemental deck for effecting removal of fractions of the lowermost strata While the lightest gravity constituent ows rearwardly and' lateraily` relatively to said banking wall and said baille. Y l i 14. A coal cleaning apparatus comprising a main elongated deck having riles set at an angle to the longitudinal axis thereof, means for feeding coal onto the deck, mechanism for operating the deck to form the coal intoa bed and to feed ,plein'ental deiek, and a baille extending partially 'the resulting bed along the deck,I a supplemental deck branching rearwardly from. the main deck, means for stratifying the said lied of coal as it moves along thej decks, relatively high retaining means along the main deck for preventing lateral 5 discharge of coal therefrom andffor directing Ithe coal fractions which pass over the riilles of the main deck onto the supplemental deck, and discharge means for discharging successive layers of the stratified bed, the said discharge means being 10 Y positioned along the main deck to discharge refuse fractions caught by the riflles thereof, and along the supplemental deck to discharge the .refuse fractions which pass over the riiiles of theA main deck. Q 1B 15. In a device of the character described, the combination with a deck having a main section and allaterally branching section, a sideboard extending along one side of the main section to the branching section and having sufficient height 2l to preient material from passing thereover, and a baille extending along said deck between said sections and in alinement withsaid sideboard, said baille tapering along its upper edgeY from the top of the sideboard ltoward said deck where the 25 main section communicates with the branching section. i i

16. 1n a device of the charagter descfribed, the combination with an upper decklsection and an inclined deck section, of a sideboard extending a@ along one side of said upper deck section to the A upper end of the inclined decl; section, riilles on both of said sections of less height thanthe height of said sideboard, andja baille ejxtending from said sideboard along the uncture between said sections,said baille tapering downwardly from the height of the sideboard to the height of said riles. Y Y g i 17. A coal cleaning fapparatus adapted to stratify a bed of coal and comprising a main elongated deck, a supplementalV deck branching from the main deck andV inclined thereto, riiiles on the decks, sideboards along the deck and meeting at an. acute angle between Athe main deck vand supacroes the deck from where the sideboards :neet at tl'ie said acute angle, the said baille being disposed substantially as an extension of the sideboard extending along the inner edge of the mainv deckrand having a height equal to the sideboards at the sideboards andgradually tapering to VVthe same height as the riilles, the said baille permittingfmaterials of lowest specic gravity in the upper strata of the bed of coal `to ildw from themain deck to the supplemental deck the point nearest the intersection of the baiile with the sideboards, while allowing successive intermediate strata of the bed toriiow onto the supplemental deck at points successivelylnearer the opposite end of the-main deck.

Y ,Y G MACK E. HAWORTH. 

